Shoulder-borne carrying straps are generally provided for use with bags, sacks, rucksacks, boxes or containers to assist a person to carry bulky, heavy or both bulky and heavy articles or items from one place to another. Shoulder straps are preferred over hand-carrying straps because the weight can rest on the shoulder ridge of the carrying person, thereby freeing the hands of the carrying person for other purposes such as attaining body balance or for self protection.
The dual shoulder loop and the single shoulder loop carrying strap systems are the two common types of shoulder carrying systems. The single shoulder loop carrying strap system (hereinafter referred to as the “single strap” system for succinctness and convenience) generally includes a length of strap having both its longitudinal ends attached to the load, thereby forming a loop of a carrying strap. In use, a person inserts one of his arms through the loop until the shoulder-engaging portion of the strap rests on the shoulder ridge of the carrying person and then lifts the load by his shoulder. In such an application, the load is usually carried on one side of the body and the load is usually borne by either shoulder on that side of the carrying person, depending on personal preferences. A typical example of a single strap system is shown, for example, in U.S. Pat. No. 5,735,398 to Price.
Since a single strap carrying system is usually used to carry a load on one side of the carrying person, a well-designed shoulder strap usually includes a padded shoulder engaging portion having a larger width than the rest of the strap to distribute weight. In a typical well-designed carrying strap, the shoulder engaging portion is usually slightly curved or has an overall parabolic shape so that the portion of the strap between the load and the shoulder engaging portion can smoothly and gradually extend towards the outside of the body without propping up the outer edge of the shoulder engaging portion.
Thus, a typical single carrying strap is usually characterised by a length-wise non-symmetrical shoulder engaging portion which is designed to accommodate the transversal shape of the shoulder ridge for user comfort as well as to mitigate the tendency of the strap to slip off the shoulder due to the overhanging load.
Because of its non-symmetry, a single strap for a load having specific orientations such as golf bags is usually adapted for use on either the left- or the right-shoulders so that different straps are needed for the left- and the right-shoulders. Hence it will be advantageous to provide carrying straps with improved user friendliness such that the single straps can be used on either shoulders.
While the single strap system is convenient for moving a load for a short distance, it is not particularly preferable for moving a heavy load for a longer distance because the strap load is localised on one shoulder ridge and this may hurt the carrying person. This is particularly so when the load being carried is a fully-loaded golf bag having an open end with a lot of loosely placed golf clubs which may jiggle, jump or bounce when the carrying person moves.
To enhance the comfort of the carrying person, a dual shoulder-loop carrying system (hereinafter referred to as the “dual strap” system for succinctness and convenience) is usually utilized. The dual strap system generally includes two strap loops which are formed by attaching two loops of carrying straps to a load. The shoulder loops are generally designed so that the arms of the carrying person are inserted through the loops until the shoulder engaging portions on the two strap loops rest squarely on the shoulder ridges of the carrying person's. Furthermore, in the dual strap systems, the weight of the load is usually quite evenly distributed across the two shoulders and the load is usually maintained near the middle of the back of the carrying person.
Common examples of applications of a dual strap system includes back-packs, rucksacks, baby carriers and golf-bags. Examples of such dual strap systems which have been particularly utilized in golf bags include U.S. Pat. Nos. 5,042,704, 5,558,258 and 6,173,874 to Izzo, U.S. Pat. No. 5,954,255 to Beebe et al., U.S. Pat. No. 6,006,974 to Varney et al., and U.S. Pat. No. 6,173,874 to Stein et al.
While a dual strap system provides enhanced comfort due to a substantially balanced weight distribution on both shoulders, the harness-like structure of a dual strap system makes it more tedious to mount and more difficult to dismount than a single strap system. Dismounting a dual strap system is more difficult because the straps usually converge towards the load and, as a result, the tension in the straps tends to pull the straps towards each other while dismounting requires pushing of the strap pair away from each other in order to remove them from the shoulder ridges.
In order to avoid the tediousness and difficulty associated with the mounting and dismounting of a load, when using a dual strap system, many people prefer to use a single strap system for moving a load for a short distance, for example, when carrying a fully-load golf-bag between hits, and, to use a dual strap system when carrying the load for a long distance. To accommodate the different usages, some golfers carry both a dual strap and a single strap system in their golf set so that the carrying systems can be used alternatively.
Thus, it will be advantageous if there can be provided carrying straps or strap carrying systems which can be convertible between a dual strap system and a single strap system as and when necessary so that a user does not have to carry two different sets of carrying straps. It will be more advantageous if such a strap system can be easily and conveniently convertible between the two forms without compromising the comfortability of the dual strap system while at the same time even possibly enhancing the comfortability of the resultant single strap system. Furthermore, it will be further advantageous if there can be provided a dual strap carrying system of the afore-said describe which can be convertible into a non-symmetrical single strap system which is equally well adapted for use both on the left or the right shoulders.
Also, it will be highly advantages if there can be provided an improved carrying strap with improved characteristics to alleviate its tendency to slip off the shoulder.
However, there are several conflicting requirements which need to be overcome, or at least alleviated, in order to provide a strap carrying system having the aforesaid-advantages or benefits. For example, since the load carried by a dual strap system tends to pull the two strap members towards each other, there is generally no need to prevent un-intentional slipping off of the straps from the shoulders. As a result, the shoulder engaging portions of the two member straps usually include a non-frictional shoulder engaging surface so that the member straps can be easily pushed away from each other and from their respective contacting shoulder ridges for dismounting.
On the other hand, a load carried by a single strap system is usually disposed on one side of the body and tends to pull the shoulder engaging portion of the strap away from the body and towards a disengaging position. To alleviate undesirable slippage of the shoulder ridge, the shoulder engaging portion of the strap member is usually provided with a non-slippery or frictional shoulder engaging surface together with a non-symmetrical transversal shape along its length.
Hence, it will be desirable if there can be provided improved carrying straps or carrying strap assemblies which provide at least some of the aforesaid benefits or advantageous while overcoming, or at least accommodating, the afore-said conflicting requirements.